Spinal cord stimulation suppresses focal rapid firing-induced atrial fibrillation by inhibiting atrial ganglionated plexus activity.

Abstract

OBJECTIVE: This study was designed to demonstrate that spinal cord stimulation (SCS) could suppress high-frequency stimulation (HFS)-induced focal atrial fibrillation (AF) at atrial and pulmonary vein (PV) sites by inhibiting atrial ganglionated plexus (GP) activity. METHODS: Multielectrode catheters were attached to atria and all PV sites. SCS was performed at the T1-T5 spinal region for 1 hour. At the baseline state and the end of 1 hour of SCS, 40 milliseconds of HFS was delivered 2 milliseconds after atrial pacing to determine the AF threshold at each site. One electrode was attached to the superior left GP so that HFS to this site induced sinus rate slowing. Microelectrodes inserted into the anterior right GP recorded neural firing. RESULTS: SCS induced a significant increase in AF threshold at all sites (all P < 0.05). The sinus rate slowing response induced by superior left GP stimulation was blunted by SCS (17% &#xb1; 3.6% vs. 39% &#xb1; 3.8%, P < 0.05). The frequency (32 &#xb1; 4 vs. 87 &#xb1; 6 impulses per minute, P < 0.05) and amplitude (0.16 &#xb1; 0.02 vs. 0.42 &#xb1; 0.04 mv, P < 0.05) of the neural activity recorded from the anterior right GP were markedly inhibited by SCS. CONCLUSIONS: SCS may prevent episodic AF caused by rapid PV and non-PV firing through modulating GP activity.